In the art of printing and die cutting sheets of material, such as corrugated paperboard for manufacturing containers, for example, it is known that die cutters may cut and slot each sheet of material so as to form a multiplicity of product portions on each sheet. By way of a simplified example, the die cutter may cut each sheet of material such that three or more cartons, or carton tops, or other product portions may be produced from each sheet of paperboard, plastic or other sheet material. This practice allows substantial economics of manufacture by efficiently utilizing the maximum square foot area of each sheet of material and minimizing the amount of waste portions of each sheet. Such sheets of material, having multiple product portions connected together by small connecting portions, are hereafter sometimes referred to as "articulated" sheets as will be more fully explained.
After the articulated sheets have been die cut, which usually follows the printing of indicia on each sheet, pluralities of sheets are stacked in relatively short bundles, and the bundles are sent to a breaker machine in order to separate the bundles into separate stacks of product portions. This breaking of bundles into separate product portions has been a long-standing problem for many reasons. For example, the ultra-high speed printing and die cutting machines of the present day, which can process 1,000 board feet per minute of sheets, require that the breaking function keep pace with the total production line. This requires that the number of sheets per bundle, and therefore, per "break," be increased over that previously possible, and the number of breaks per unit of time must be increased. Secondly, the break must be "clean" with no tears in the product portions. Furthermore, some connecting portions must not be broken along straight lines, but rather, along right angles and rounded connecting portions between product portions such as in the cases of "nested" or "lock bottom" sheets, respectively.